1. Field of the Invention
The present invention relates to a control device for multiple lamp currents of a liquid crystal display (LCD) backlight source. More particularly, the present invention relates to a control device for multiple lamp currents of a liquid crystal display (LCD) backlight source, through which luminance of the lamps in the LCD backlight source may be maintained balanced.
2. Description of the Prior Art
Referring to FIG. 1, an architecture diagram of a conventional control circuit of multiple lamp currents in a liquid crystal display (LCD) backlight source is shown therein. As shown, the multiple lamps in the LCD backlight source are controlled in the following manner. An electronic power switch 12 is connected to a primary side of a transformer 11 and four lamps are connected at one end in parallel to a secondary side of the transformer 11. At the other end of the four lamps 13, three inverters 14 are connected at one end, which are connected to an integrated circuit (IC) feedback control module 15 at the other end. Further, the IC feedback control module 15 is connected to the electronic power switch 12. As such, the control circuit for the multiple lamps 1 is completely formed. By means of the IC feedback control module 15, a feedback current signal is detected and determined and processed. Then, a control signal is outputted to the electronic power switch 12 by which an output signal from the electronic power switch 12 is controlled, thereby achieving control and maintenance of uniform luminance of the lamps. Since N lamps in the above circuit requires N−1 inverters, a considerable limitation is caused on manufacturing cost and use of such circuit. Further, since too many components are involved in the circuit, the current balance purpose is difficult to be achieved.
In view of the above discussion, the conventional control circuit for the multiple lamps still has some shortcomings to be addressed and thus has to be improved. Accordingly, the Inventors have paid many efforts in the related research and finally developed successfully a control device for lamp currents of a LCD backlight, which is taken as the present invention.